1. Field of the Invention
The present invention relates to construction methods for constructing a building, such as a residential structure, which has storm protection features and, more specifically, to a tornado resistant/proof residential dwelling structure.
2. Description of the Prior Art
A variety of storm resistant building/shelter systems are known in the prior art. These systems are intended to protect against such catastrophic events as hurricanes and tornados where potentially deadly destructive forces such as high wind velocities and high pressure differentials (as associated with tornados) and high wind and rain (as associated with hurricanes) exist.
The present invention could be applied to storm resistant buildings of a variety of types. However, the invention has particular applicability to tornado resistant/proof residential structures. Certain geographical areas are known to suffer from a high incidence of tornados. Generally, tornado-prone areas occur at middle latitudes where cold, dry air at a high altitude in the atmosphere meets warm, moist tropical air closer to the surface of the earth. For example, the central United States is prone to tornadoes because cold, dry air from the Rocky Mountains often meets moist, warm air from the southeastern United States. The damage to buildings, including residential dwellings, is extremely costly and, even worse, often includes loss of life. People are often injured or killed from total or partial collapse of the structure they are in, or from flying debris if they are not able to find adequate shelter in time. Tornados are capable of producing deadly air funnels with winds moving at 100 to 250 miles per hour or more. Tornadoes travel forward at an average speed of 35 miles per hour and their paths often cover as much as hundreds of yards in width. Because of their awesome destructive power, it is critical that human beings be able to find a strong protective shelter fast.
To reduce tornado injuries, people often find shelter in the basement of their homes. However, many people live in structures which have no basement. For people who live in a structure without a basement, other types of tornado protection shelters exist, often separate from the dwelling. However, these forms of tornado protection are limited because they require time for people to obtain shelter within the structure after they realize a tornado is approaching. This is difficult because of the unpredictable nature of tornadoes and the speed with which they form and travel. Thus, there is a need for a tornado resistant building design that encompasses an entire building structure, while at the same time providing a comfortable residence.
A brief survey of tornado resistant/proof structures includes the following: U.S. Pat. No. 1,706,496, is a very early patent on an “earthquake and tornado proof building” which, while probably not practical today, shows the long standing need for a solution to the problem at hand.
U.S. Pat. No. 4,126,972, describes a “tornado protection building”, one of the rooms of which has a tornado protection assembly extending across the top and sides of its interior, the building having a concrete slab under it, into which the protection assembly is anchored. The “storm proof room” is intended to resist forces in all directions exerted by a tornado, thereby protecting a first floor space which is part of a small, basement-less house.
U.S. Pat. No. 6,393,776, discloses a protective shelter for installation above and in the ground including a superstructure style frame, a composite wall structure for absorbing energy from forceful impacts, and a tub encased in a foundation. The tub provides a downward force such that the superstructure is not floated out of the excavation when the encasement is poured.
U.S. Pat. No. 7,921,604, describes an aluminum-foam structural housing unit that is stormproof, self-contained, and built to withstand natural disaster conditions resulting from hurricanes, tornadoes, earthquakes, and fire. The unit is buoyant during flooding conditions and lifts from the ground where it is guided by vertical poles to maintain a horizontal orientation. The unit also automatically disconnects from public utility systems as lifting occurs, and it then provides its inhabitants with self-contained sources of water, electrical energy, and sewage management.
U.S. Publication No. 2009/0013621, shows a tornado resistant structure which includes a base and a building structure positioned on the base. The building structure includes a plurality of deflection walls and reinforced corners and a plurality of skylights carried on a roof of the building structure.
The building structure includes an entrance and a drain positioned proximate to the entrance. The above discussion is not intended to be exhaustive, but merely illustrative of the types of structures and systems that have been envisioned in the prior art to address the problem of the tornado resistant/proof structure.
The more practical of the prior art structures are probably those which incorporate a “safe room” built within the traditional residential dwelling structure, as well as the known building systems where the entire external wall structure of a residential structure is built of reinforced concrete, or the like. A primary problem with the “safe room” approach is that everyone may not make it into the protective space in time. One disadvantage of the overall concrete “bunker” building approach is that such structures tend to be unattractive or down right unsightly and would not be allowed in many modern home subdivisions.
Thus, a need continues to exist for a tornado resistant/proof building, particularly a residential dwelling structure, which encompasses an entire building structure, not just the external sidewalls or an internal “safe room” and yet which has the appearance of a traditional, comfortable residence.